The number of realizable processing stations is limited in a production installation, for example, a press. The product cannot be manufactured from the work piece in a single pass within the production installation if a great number of processing stations are required for manufacturing a work piece. It is then necessary to perform two consecutive passes in a production installation and to exchange the processing stations and/or tools after the first pass of the work pieces and/or to provide two production facilities having the various suitable stations in order to manufacture the product.
A processing station of a press features one respective tool. Six such tools are typically disposed in a row. The pressing force of the press is, however, often significantly higher than the pressing force required for using the tools. The surface available under the press slide is to some extent also not used by the tools.
A transport device for transporting work pieces along the processing stations of a transfer press usually consists of two gripper rails extending in the transport direction of the work pieces. In addition to the longitudinal movement and the lifting movement, the gripper rails perform an additional transverse movement, wherein gripper elements are provided at the gripper rails for gripping and/or advancing the work pieces from one processing station to the next. The possibilities of movement of the gripper rails and gripper elements are generally cleverly distributed. The gripper elements take care of the movement along the gripper rail, for example, so that the gripper rail no longer needs to implement this movement itself.
Most of the time, the transport device is disposed in the production installation laterally outside of the processing station. In order for the gripper rails and the gripper elements to not interfere with the processing operation of the press within the tool area, the gripper rails must be moved back out of the tool area, for example, laterally.
Conventional tri-axial transfer devices comprise, for example, two grippers disposed opposite each other at respectively external gripper rails. The grippers are grippingly disposed on two sides opposite each other with an offset of, for example, a specific degree value (in particular 180°). The two gripper rails with the grippers can perform synchronous and independent, partly symmetrical movements, which can, however, only be performed in the same direction of movement along the lifting, closing and/or feed axis (transport axis).
A conventional tri-axial transfer system with two opposite grippers and external gripper rails is described, for example, in DE 10 2011 118 216 B4 for a transport along consecutive processing stations in a throughput direction.
DE 40 22 560 C2 describes a multi-station processing apparatus with a transfer installation for successively transporting the work pieces from one processing station to the next in which the processing stations are disposed in a staggered manner on two opposite lines. The gripper arms here transport the work pieces in a regular zigzag line.
DE 10 2004 044 767 A1 describes an assembly for transporting work pieces in a manufacturing line, wherein work pieces are transported on pallets by a pallet loading portal along a line in a main conveying direction, and the work pieces are discharged perpendicularly to this main conveying direction so that the work pieces reach the processing stations. The processed work pieces are then transported by a roller conveyor along a line in the opposite direction to the main conveying direction, wherein the roller conveyor can allow for a flexible reversible material flow.
DE 10 2005 034 079 A1 describes a modular manufacturing system with an agent-based assignment of orders. A manufacturing plant with a handling installation and several modular manufacturing stations is described in DE 10 2009 003 492 A1.
DE 20 2013 102 852 U1 describes a processing installation with a conveying installation by which work pieces are transported by a work piece carrier using their own weight and gravity.